The ConnectionRequestEvent represents a ConnectionRequest and
might be vetoed by (depending on the firing observable) throwing a
VetoException or VetoException.VetoRuntimeException by the according
Observer.

The GenericConnectionRequestEvent represents a
ConnectionRequest and might be vetoed by (depending on the firing
observable) throwing a VetoException or VetoException.VetoRuntimeException
by the according Observer.

The GenericNetworkRequestEvent represents a ConnectionRequest
for a connection and might be vetoed by (depending on the firing observable)
throwing a VetoException or VetoException.VetoRuntimeException by the
according Observer.

The NetworkRequestEvent represents a ConnectionRequest for a
connection and might be vetoed by (depending on the firing observable)
throwing a VetoException or VetoException.VetoRuntimeException by the
according Observer.